Security readout for executives and security teams
Plain-English summary
CVE-2026-26271 affects FreeRDP clients before 3.23.0. A malicious or intercepted RDP server can send crafted window icon data that causes FreeRDP to read beyond a buffer. The documented impact is limited availability impact, so the main business concern is client instability or disruption during RDP use, not confirmed data theft or system takeover.
Executive priority
Treat as a routine but timely client-side update. Prioritize environments using FreeRDP for remote administration or third-party RDP access. There is no cited active exploitation, and documented impact is availability-limited, but network reachability and low attack complexity justify prompt patching.
Technical view
FreeRDP before 3.23.0 has a CWE-126 buffer overread in freerdp_image_copy_from_icon_data() in libfreerdp/codec/color.c. The issue is triggered while processing crafted RDP Window Icon TS_ICON_INFO data from an RDP server or man-in-the-middle. CVSS v4.0 is 5.5, AV:N/AC:L/PR:N/UI:N, with low availability impact only.
Likely exposure
Organizations are exposed where users, jump hosts, tools, or embedded workflows run FreeRDP versions earlier than 3.23.0 and connect to untrusted, compromised, or intercepted RDP servers.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. Exploitation requires the vulnerable FreeRDP client to process malicious icon data supplied by an RDP server or man-in-the-middle. Public sources identify a fix commit and advisory, but no weaponized exploitation evidence is provided here.
Researcher notes
The key code path is freerdp_image_copy_from_icon_data() handling TS_ICON_INFO icon data. The advisory states reachability from an RDP server or man-in-the-middle. The fix is identified in commit f5e20403d6e325e11b68129803f967fb5aeec1cb. Evidence provided does not establish confidentiality impact, integrity impact, or active exploitation.
Mitigation direction
- Upgrade FreeRDP to version 3.23.0 or later.
- Prioritize systems that connect to external or less-trusted RDP servers.
- Limit RDP connections to trusted servers where feasible.
- Monitor vendor advisory for any additional guidance.
Validation and detection
- Inventory endpoints, jump boxes, and applications using FreeRDP.
- Confirm installed FreeRDP versions are 3.23.0 or later.
- Review package manager and container images for bundled FreeRDP libraries.
- Check RDP client usage against untrusted or internet-accessible servers.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-126: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-26271 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.5MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hr4m-ph4g-48j6CVE reference · x_refsource_CONFIRM
- https://github.com/FreeRDP/FreeRDP/commit/f5e20403d6e325e11b68129803f967fb5aeec1cbCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Buffer Over-read
Buffer Over-read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.